24th ABCM International Congress of Mechanical Engineering December 3-8, 2017, Curitiba, PR, Brazil COBEM-2017-1954 COMPLEX FLUID FLOW THROUGH A CONSTRICTED MICROCHANNEL José Angel Florián Gutiérrez, Maria Moura, Marcio Carvalho Pontifícia Universidade Católica do Rio de Janeiro (PUC) – Department of Mechanical Engineering Rua Mârques de São Vicente, 225, Gávea – Rio de Janeiro, CEP 22451-900, RJ - Brasil [email protected]; [email protected]; [email protected]Abstract. This work presents a study of the flow of a viscoelastic solution of PEO (0.1 wt% Polyethylene Oxide solution) through a constricted glass microchannel, used as model for a pore-throat geometry of a porous media. Pressure drop measurements are performed and flow velocity fields are obtained using the micro particle image velocimetry (micro-PIV) technique. Experiments with a viscous solution of glycerin (61 wt% glycerin in water), of similar shear viscosity to the PEO solution, were also performed to investigate elastic effects of the PEO solution. Non-linear pressure drop behavior due to extensional effects of the PEO solution were observed. The velocity fields of the glycerin solution showed a permanent regime for the entire flow rate range explored, while the PEO solution shows changes in the direction of the flow and velocity fluctuations over time for high flow rates. In addition, the presence and growth of vortices (upstream of the constriction) were observed for the PEO solution. This study provides important information on how viscoelastic polymer solutions behave in a porous media and can impact their use in Enhanced Oil Recovery. Keywords: Microfluidics, Viscoelasticity, Elastic turbulence, PEO Polymeric solution, Micro-PIV 1. INTRODUCTION Polymeric solutions are used to modify flow in various applications, the most common being enhanced oil recovery. The sweep efficient of water injection in an oil reservoir (secondary oil recovery) is limited due to a high mobility ratio between the water and oil. This promotes a non-ideal displacement behavior called fingering. Polymeric solutions are used to improve oil recovery due to their higher viscosity when compared to water. Viscoelastic properties of the polymeric solutions may also change the pore-scale flow behavior and reduce the residual oil saturation. However, polymer injections are still not well understood. Microfluidic devices can be used to represent porous media and study the effects of viscoelasticity at the micro-scale. “Recently, Miranda (2015)” performed injection tests of three different fluids - water, a viscous solution of glycerin, and a viscoelastic polymeric solution of PEO - in an oil saturated glass microfluidic device (pore network and channels). They observed that the PEO injection produced a greater displacement of oil ganglia and a lower residual oil saturation than the glycerin and the water injections, as shown in “Fig. 1”. The higher mobilization of oil ganglia observed with the injection of the PEO solution was associated with the lower water mobility at the pore scale and the extensional behavior of the PEO solution. As a consequence, a lower residual oil saturation was obtained. Recent studies have shown pressure drop increase in the flow of viscoelastic liquids through constrictions. “Clarke, et al., 2015” used particle tracking velocimetry (PTV) to visualize the injection of HPAM viscoelastic solutions in a microfluidic device (pore network and channels) and observed velocity fluctuations associated to pressure drop increase. “Boek, et al., 2006” analysed the behavior of EHAC polymeric solutions flowing through a microchannel with expansion-contraction geometry using micro-PIV. They showed that the water flow is stable, but the EHAC solution exhibits velocity fluctuations in the contraction region. These velocity fluctuations were linked to the phenomena called elastic turbulence (transition from steady laminar flow to a strongly fluctuating flow).
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24th ABCM International Congress of Mechanical Engineering December 3-8, 2017, Curitiba, PR, Brazil
COBEM-2017-1954
COMPLEX FLUID FLOW THROUGH A CONSTRICTED
MICROCHANNEL
José Angel Florián Gutiérrez,
Maria Moura,
Marcio Carvalho
Pontifícia Universidade Católica do Rio de Janeiro (PUC) – Department of Mechanical Engineering
Rua Mârques de São Vicente, 225, Gávea – Rio de Janeiro, CEP 22451-900, RJ - Brasil